Since most of the attention to my article seems to be regarding the remen/cubit relation, I decided to add a couple of pages to the beginning of the article to hopefully clarify it. I quoted a good bit from two of the Griffith articles that you mentioned. Here are the links if you want to take a look at them:
this is the first one from 1892 - the chart that is in between pages 410 and 411 says that the square remen as half of the square arura is given in Kahun, Rhind, Berlin and Harris papyrus and inscriptions at Edfu.
Here is the second one